The contact between the metasedimentary Fauquier Formation (uppermost marble member) and the overlying metavolcanic Catoctin Formation is exposed in an abandoned quarry north of Aldie, Virginia, across Goose Creek from Lime Kiln Road. The nature of this contact (is it conformable? does it show primary or tectonic structures?) is of potential importance in constraining the age of the youngest "Snowball Earth" glacial event.